Minimagick error during upload “composite -compose Over -gravity North”

问题

I am trying to upload an image by gem "carrierwave", "~> 1.1.0" and gem "mini_magick", "~> 4.7.0" to upload image. I am getting this error.

I am using this code to upload image.

  MiniMagick::Tool::Convert.new do |i|
    i.size "#{image_width.ceil}x#{watermarked_image_height.ceil}"
    i.gravity "center"
    i.xc "white"
    i << temp_image_path
  end
  @_watermarked_image = MiniMagick::Image.open(temp_image_path)
  @_watermarked_image = @_watermarked_image.composite(source_image, "jpg") do |c|
    c.compose "Over"
    c.gravity "North"
  end

:ERROR

composite -compose Over -gravity North /tmp/mini_magick20190710-1-g0dcpy /tmp/mini_magick20190710-1-1fil3d9.jpg /tmp/mini_magick20190710-1-ibbwos.jpg` failed with error:\\n

来源：https://stackoverflow.com/questions/57038764/minimagick-error-during-upload-composite-compose-over-gravity-north